Method of increasing oil extraction from oil-bearing strata



Dec. 3 1 1,520,737

Y R. L, WREGHT METHOD OF INCREASING OIL EXTRACTION FROM OIL BEARINGSTRATA Filed April 26, 1924 INVENTQR.

Patented Dec. 30, 1924.

ROBERT L. WRIGHT, OF FORT DODGE, IOWA.

METHOD OF INCREASING OIL EXTRACTION FROM OIL-BEARING STRATA.

Application filed April 26, 1924. Serial No. 709,098.

To all whom it may concem:

Be it known that I, ROBERT L. VVRIGHT, a citizen of the UnitedStates,and a resident of Fort Dodge, county of \Vebster, and State ofIowa, have invented a new and useful Improvement in Methods ofIncreasing Oil Extraction from Oil-Bearing Strata,-of which thefollowing is a specification, the principle of the invention beingherein explained and the best mode in which I have contemplated applyingthat principle, so as to distinguish it from other inventions.

The present invention relates to a process for increasing the oilextraction from oil bearing strata, and more particularly to means foraiding the natural means by which oil is extracted. This is done. byaltering or changing the conditions in the natural oil containingstrata'so as to make them more favorable for the natural forces to movethe oil from the containing strata into the well or chamber from whichit may be pumped or withdrawn to the surface.

In extracting oil in its natural accumulation, the confined and absorbedgases are the principal agents in driving and carrying the oil from thepoers or voids of the contain-- ing strata to the well. This actiontakes place, due to the reduction of the pressure 0 at the well casingallowing the gases .to move in this direction to carry and force the oilwith the gas. The movement of the oil is resisted and retarded by thefrictional resistance of the containing strata, and also by the inherentphysical properties of the oil, and in some cases by the pressureexerted by a column of fluid standing in the well casing. The presentinvention assists these natural forces by forming artificial drainagechannels from the well casing or from a chamber at the bottom thereofout into the oil bearing strata, these channels starting from a pointbelow the strata and inclining upwardly and radially from the ca;- ing.In distinction to present methods, the gas and oil in the voids of thestrata, do not have far to flow through the strata pores, most of whichare of capillary size, i

'the gas into the sump. The channels of before reaching a channel ofsuper capillary size, through which it will 'fiow freely by gravity. Tofurther assist and increase-the amount of oil obtained, it is desirableto supply heat to the channels so as to tend to expand existing gas, toliberate more gas which is absorbed in the oil present in, the

oil bearing strata, and to volatilize some of the liquid hydrocarbonsand thus increase the flow of both gas and oil. To the accomplishment ofthe foregoing and related ends, said invention, then, consists of themethod hereinafter fully described and particularly pointed out in theclaims.

The annexed drawing and the following description set forth in-detailone approved method of carrying out the invention, such disclosedmethod, however, constituting but one of the various ways in which theprin ciple of the invention may be used.

In said annexed drawing Fig. 1 is a diagrammatic vertical sectional viewshowing the general layout of the present invention; Fig. 2 is adiagrammatic horizontal section showing relative are-as reached; andFig. 3 is a vertical section through the chamber, room and lower portionof the well casing.

In the drawing there is illustrated an oil well comprising the usualaperture 1, from the surface of the ground down through and into the oilbearing strata 30, and as shown in the drawing, this well or hole isextended below the oil bearing strata and is there enlarged into achamber 2, the lower portion of which also acts as an oil sump 20. Inthe present invention this hole is made of considerable size, about 5feet in diameter, large enough to receive a hollow shaft or well casing3, this well casing being of sufiicient internal diameter to allow forelevator mechanism for access to the lower room and for the handling ofnecessary machinery. The casing is extended the full len h of the wellor hole until it reaches thechamber at the bottom and is there pro videdwith a room 4, which is sealed to the casing, but this room does nottake up the entire space in the chamber. From the chamber are drilledseveral series of upwardly inclined channels 5, which extend radiallyfrom the chamber, and these chan- 1 nels are. extended up into andsubstantially through the oil bearing strata and form the drainagechannels for the oil and each series are at a different-inclination and10 the number of series will depend upon the area to be drained and thethickness of the .oil'bearing strata. In the casing is mounted an outletipe 6 for the gases, and this pipe is exten ed through the room into thechamber and thus into open communication with the channels so as toprovide an escape tor the accumulated gases.

From the room are extended'a series ofheating pipes 7 which are run outinto the channels, but which are smaller than the.

. able pipe 11, and which islikewise connected to an outflow oil pipe 12extending up through the well casing. In using the heating pipes theymay be either closed at the ends so as to form mere heating chamberswhich heat the oil strata by radiation from the pipe, or they may beperforated in certain instances to actually force steam out into the oilbearing strata to help vaporize and carry the oil back down the channelsto the sump. Y

By the present proposed method a single well can be made to extract theoil from a very large ground area and it is particularly useful wherethe oil bearing strata is of the type which prevents the free flow ofoil, or in such fields as where the wells must be driven close togetherin order to obtain the best results. It is also applicable to fieldswhich have been partially exhausted, as the large casing may be placedin the middle of an oil bearing area and the laterals run out so as totap many of the pockets throughout the oil bearing strata which do notnaturally release the oil to a single small well hole of the usual type.

Other modes of applying the principle. of my invention may be employedinstead of the one explained, change being made as regards the methodherein disclosed, provided the step or steps stated by any of thefollowing claims or the equivalent of such stated step or steps beemployed.

I therefore particularly point out and distinctly claim as myinvention 1. The method of increasing oil extraction from a wellcomprising the formation of a well casing extending below the oilcontaining strata forming a. chamber around from a well comprising theformation of a well casing extending below the oil containlng strataformlng a chamber around the bottom of said casing, running a series ofradially extending channels laterally and inclined upwardly from saidchamber into the oil bearing strata and supplying heat through saidchannels.

3. The method of increasing oil extraction from a well comprising theformation of a well casing extending below the oil containing strataforming a chamber around the end of said Casing to form a sump, drillinga series of laterally extending upwardly inclined channels from saidchamber into the oil bearing strata, and pumping the accumulated oilfrom said sump.

4. The method of increasing oil extraction from a Well comprising theformation of a well casing extending below the oil containing strataforming a chamber around the end of said casing to form a sump, drillinga series of laterally extending upwardly inclined channels from saidchamber into the oil bearing strata forming a closed room in saidchamber and connected to said well casing, running a series of heatingelements from said room out into such lateral channels, and pumping theaccumulated oil from said sump.

The method of increasin oil extraction from a well comprising the iormation of a well casing extending below the oil-containing strataforming a chamber around the end of said casing to form a sump, drillinga series of laterally-extending upwardly inclined channels from saidchamber into the oil bearing strata, forming aclosed room in saidchamber and connected to said well casing, running a series of heatingelements from said room out into such lateral channels, pumping theaccumulated oil from said sump and providing a gas outlet pipe in saidwell casing opening into said chamber.

'6. The method of increasing oil extraction from a well comprising theformation of a well casing extending below the oil containing strataforming a chamber around the end of said casing to form a sump, drillinga series of laterally extending upwardly inclined channels from saidchamber into the oil bearing strata, forming a closed room in saidchamber and connected to said well cas ing, running a series of heatingpipes from said room into such channels, supplying a heating medium tosaid pipes, pumping the accumulated oil from said sump and providing agas outlet pipe in said well easing opelh ing into said chamber.- I

Signed by me, this 26 day of March. i921.

ROBERT L. wmon'r.

